Still unstable two years after its revolution, Tunisia now must contend with the aftermath of a political leader's murder – including the formation of a new government.

Amine Landoulsi/AP

Tunisians demonstrate outside the home of Tunisian leader Chokri Belaid after he was shot to death in Tunis, Wednesday. It's not clear who gunned down Mr. Belaid, an opposition politician and fierce government critic, or why.

Tunisia has weathered riots, political squabbling, and economic crisis since protests toppled its former dictator two years ago, kickstarting the Arab uprisings. Today, this fledgling democracy suffered a new blow: its first murder of a political leader, which prompted the prime minister to dissolve his government.

It’s not clear who gunned down Chokri Belaid, an opposition politician and fierce government critic, or why. But his death highlights both the fragile security and fraught political climate in Tunisia, where leaders and citizens alike are still getting the hang of democratic rule.

Tunisians made history in January 2011 by forcing then-President Zine al-Abidine Ben Ali from power after a two-decade rule. The following October, elections were swept by the moderate Islamist Al Nahda party (also known as the Ennahda party, which now leads a coalition government it formed with two secularist parties.

The government has struggled, however, to relieve economic malaise that deepened after Mr. Ben Ali’s removal as uncertainty spooked tourists and investors. Critics have also blasted Al Nahda in particular for failing to discipline violent Islamic extremists, as well as rowdy pro-government groups.

Mr. Belaid was such a critic. Just yesterday, he used a press conference to accuse Al Nahda of ignoring violence by the Committees to Protect the Revolution – pro-government activists who say they aim to root out elements of Ben Ali’s regime and have brawled with antigovernment protesters.

“There are groups within Al Nahda that … are pushing the country toward violence,” he told Tunisia’s Nessma TV at the Tunis headquarters of the Popular Front, a grouping of leftist opposition parties of which he was a leading member.

This morning, Belaid was shot several times as he left his house. He was taken to a nearby clinic, where he died, reported The Associated Press. According to Ziad Lakhader, a Popular Front leader quoted by Reuters, Belaid was struck by four bullets to the head and chest.

Human Rights Watch urged Tunisian authorities to bring Belaid’s killers to justice, reversing what it describes as a failure to crack down on violence.

“This assassination is the gravest incident yet in a climate of mounting violence,” said Eric Goldstein, the group’s deputy Middle East and North Africa director. He cited attacks on journalists, activists, artists, and others, “many of which the authorities did not investigate, let alone prosecute.”

'Ignoble crime'

Al Nahda's leader, Rached Ghannouchi, called the killing an “ignoble crime,” AP reported, and urged authorities to bring the perpetrators to justice. President Moncef Marzouki, from the secularist Congress for the Republic party, vowed that Tunisia would overcome attempts to derail its democratic transition.

Tunisian democracy will depend in part on cooperation among leaders. The governing coalition must tackle economic and security problems, and hold new elections expected this summer. At present, it has been stricken for weeks by squabbling over a long-delayed ministerial reshuffle.

Thousands of Tunisians who took to the streets today to protest in Tunis and other cities condemned not only Belaid’s killing, but also the government that they say bears responsibility for broader problems. In the capital and elsewhere, police fired tear gas to disperse crowds.

“Everyone here is calling for a new revolution,” says Rachid Fettini, a businessman in the rural town of Sidi Bouzid, where uprisings against Ben Ali erupted two years ago.

Protesters in Sidi Bouzid set fire to the police station, he says, with some accusing security forces of complicity in Belaid’s killing. By this evening, police were absent, while Army soldiers – typically trusted by ordinary people – had deployed amid general calm, Mr. Fettini says.

Fettini says he has no political affiliation, although he is critical of what he calls the government’s failure to ensure order and prosperity. Beyond that, he says, “I’m afraid to see the country reach this point – where democrats can be assassinated.”